Add nanopi_gpio/README.md

nanopi_gpio/README.md

@@ -0,0 +1,22 @@
+https://forum.armbian.com/topic/5647-nanopi-neo-wiringnp-missing-sunxi_infosys_info/
+
+`/etc/sys_info/`
+```
+sunxi_platform    : Sun8iw7p1
+sunxi_secure      : normal
+sunxi_chipid      : 2c21020e786746240000540000000000
+sunxi_chiptype    : 00000042
+sunxi_batchno     : 1
+sunxi_board_id    : 1(0)
+```
+
+in the file `wiringPi/boardtype_friendlyelec.c` look for the lines:
+
+```
+   if (!(f = fopen("/sys/class/sunxi_info/sys_info", "r"))) {
+        if (!(f = fopen("/etc/sys_info", "r"))) {
+            LOGE("open /sys/class/sunxi_info/sys_info failed.");
+            return -1;
+        }
+    }
+```